Mario Bros II is a fan-made game based on the Game & Watch LCD device just titled Mario Bros.

The Mario Bros are working in a bottling factory and have to move crates with bottles and place them on conveyor belts. The player can use two joysticks to move the two brothers up and down, making sure they catch all crates as they are about to fall off a belt. When a crate is catched it is placed on a higher-up belt. Miss a crate and it will fall and break, and the mario brothers are yelled at by their bosses.

With each passing through the machine in the middle, the crates go up and at the end of the line the crate is filled and sealed. At the final point it is thrown into the truck, ready to be shipped off. When the van is filled with 8 crates it rides off and the bros get a short break, after which the game continues with increased difficulty.